Modern data storage devices such as disc drives are commonly used in a multitude of computer environments to store large amounts of data in a form that is readily available to a user. Generally, a disc drive has a magnetic disc, or two or more stacked magnetic discs, that are rotated by a motor at high speeds. Each disc has a data storage surface divided into data tracks where data is stored in the form of magnetic flux transitions.
A data transfer member such as a magnetic transducer is moved by an actuator to selected positions adjacent the data storage surface to sense the magnetic flux transitions in reading data from the disc, and to transmit electrical signals to induce the magnetic flux transitions in writing data to the disc. The active elements of the data transfer member are supported by suspension structures extending from the actuator. The active elements are maintained a small distance from the data storage surface by a fluid bearing generated by fluid currents caused by the spinning discs. The term “fluid bearing” is synonymous with the widely used term “air bearing” where the fluid utilized in the disc drive is air. Alternatively, the term “fluid bearing” is applicable to other embodiments utilizing a fluid other than air, such as helium.
A continuing trend in the data storage industry is toward ever-increasing the data storage capacity and the processing speed while maintaining or reducing the physical size of the disc drive. Consequently, the data transfer member and the supporting structures are continually being miniaturized, and data storage densities are continually being increased. One result is an overall increased sensitivity to vibration as a percentage of track width.
One source of vibration comes from the fluid currents, or windage, that is created by the spinning discs. Fluid flow perturbations, and especially turbulent fluid flow, can excite the actuator and/or the disc creating vibrations. During servo track writing operations, for example, such vibrations can create actuator positional control errors, or transducer positional “wander,” resulting in irregular servo track formatting such as but not limited to track squeeze.
While various proposed solutions have been found operable, there remains a continued need for improvements in windage management for attenuating excitation energy. It is to such improvements that the claimed invention is generally directed.